The present invention relates to blood coagulation tests and particularly to such tests performed in vitro.
It is desirable to assess and monitor blood characteristics including hemostasis (cessation of venous or arterial bleeding), clotting or thrombus formation, and thrombolysis (dissolving or shrinking clots in the blood stream) for a variety of medical procedures as for example treating blood disorders such as hemophilia, performing surgery, and blood transfusions. Such blood assessments are required promptly for surgical procedures, emergency room treatments, or blood transfusions and must be performed without the benefit of laboratory test conditions. In addition, aging and handling of a blood sample have significant effect on the blood clotting mechanism. Therefore it is necessary to provide a simple, on-site technique for in vitro assessment of blood characteristics as soon as practicable after a blood sample is drawn. The technique must also provide reliable, reproducible results.
My U.S. Pat. No. 5,339,830 is directed to a system for assessment of blood coagulation characteristics. The system includes a cartridge for collecting, assessing, and disposing of a blood sample. Hemostasis, clot formation, thrombolysis, and platelet collagen interaction properties of a set of blood samples drawn from a patient may be evaluated. The system further includes a test analyser for receiving the cartridge and for performing tests on individual sample cartridges.
As disclosed in said patent, in vitro blood analysis is performed reliably and repeatably immediately after sample collection under test conditions of constant temperature, pressure, and flow rate with minimal manipulation, agitation, and mechanical stress of the sample and without the use and disposal of supplies and related apparatus for stirring agents such as paraffin and saline solution. Bleeding aperture geometry is precisely controlled for achieving test repeatability and reliability. Disposal is limited to a test cartridge entirely containing the waste blood sample.